The third-largest city in the United States, Chicago, Illinois, has a population of about 2.8 million, 22 percent of whom are foreign born. Situated on the southwest shore of Lake Michigan, the city has served as a major port and commercial center for the midwestern section of the United States since the 19th century.

Chicago is called "The Windy City," not only because of the stiff winds off Lake Michigan but also because of its history as a town of political hustle, machine politics and labor organizing.

Much of the city's political dynamic relates to its history as a magnet for immigrant laborers seeking work in the stockyards and factories of the city in the 1800s. With the arrival of the first railroad in 1848, farmers from surrounding states began sending their cattle to be slaughtered and their agricultural products to be processed in Chicago plants. This increase in production coincided with one of America's largest waves of European immigration. As a result, Chicago's population had tripled by the 1860s as an immigrant workforce flowed in to take advantage of the many available jobs.

German and Irish immigrants arrived first, with Polish immigrants arriving soon after in the 1880s. By the end of the 19th century, Chicago's population had swelled to more than a million, making it one of the fastest-growing cities in the world. The city owed much of its success to the many immigrants, willing to work in exchange for the promise of a better life.

However, these immigrants were often greeted with appalling and hazardous working conditions. Determined to realize the "American Dream," many were moved to action. Upton Sinclair's classic muckraking book, The Jungle, was written about Chicago's meatpacking industry. Famed labor activist Saul Alinsky, son of Russian-Jewish immigrants, organized workers in the city's stockyards.

Perhaps Chicago's most momentous and controversial contribution to the American labor movement occurred in early May, 1886. On May 1, 80,000 workers marched through downtown Chicago, demanding an eight-hour workday. The number of protestors alarmed business leaders who demanded police crackdown on what they perceived to be anarchists.

On May 3, unarmed striking workers at Chicago's McCormick Reaper Works factory clashed with police who ended up killing several workers. In response, workingmen met at the Haymarket Square on the evening of May 4. What began as a peaceful gathering ended in bloodshed when a bomb was thrown into the crowd as police attempted to disperse the meeting. One policeman died instantly; 11 other people were killed when police opened fire in response to the explosion. Eight anarchist and labor activists were eventually arrested for the policeman's death; five were hung publicly the following year.

That march and the events of the following days are believed to be the origins of today's May Day observances.The series of events is known as the "Haymarket Affair," and because of suspicious and disputed elements surrounding the accused men's trial, many have come to refer to the eight as the "Haymarket Martyrs."

Immigration in the United States peaked between 1890 and 1920, when the country took in more than 18 million new citizens. That explosion led the U.S. government to enact the Immigration Act of 1924, which set a quota for the number of immigrants entering the United States. Initially, immigration from within North America was exempt from this act, but measures were quickly taken to deny legal entry to Mexican workers.

New arrivals to Chicago at this time were native-born rural-to-urban migrants, mostly African Americans from the southern states. Although other northern cities also expanded during this period of south-to-north migration (known as the Great Migration), Chicago was the primary destination for many blacks. With churches assisting the new residents with housing and employment, Chicago offered a more hospitable environment for migrants.

Mexicans began settling in Chicago around the turn of the 20th century, many driven north by the Mexican Revolution. They took advantage of both war-time and labor-dispute opportunities to enter the workforce. The first wave of Mexican immigrants came during World War I to work in the steel mills and established a viable community, primarily on Chicago's South Side. Both Mexicans and African Americans were hired to break strikes in the steel and packinghouse industries in 1918 and 1919.

But the Great Depression of the 1930s sent many immigrants home, including Mexicans. With a scarcity of jobs around the country, immigrants faced the same question that is raised, and remains unanswered, today: Should foreigners take jobs away from U.S. citizens? By the end of that decade, Chicago's Mexican community had shrunk by nearly 30 percent.

World War II brought a reversal in the repatriation trend. The country experienced a major labor shortage as the American workforce was drafted to serve in the war. The United States entered into an agreement with Mexico to allow temporary workers into the country. The government's bracero, or guest worker, program saw thousands of Mexicans arrive in Chicago to work on the railroad and in the garment industries. But while the United States expected those workers to return to Mexico at the end of the war, many did not.

The community continued to grow at a rapid pace. By the 1960s, Chicago was the third-largest Mexican city in the United States, behind Los Angeles, California, and San Antonio, Texas. Today, Mexican immigrants have established themselves as an integral part of the social, political and economic fabric of the city. The 2000 census showed that half a million Mexicans live in Chicago, with another 1.1 million in the greater metropolitan area. They remain the city's largest ethnic community.

Death in the Desert
Originally broadcast in June 2004, this story from FRONTLINE/World reporter Claudine LoMonaco investigates illegal Mexican border crossings through the eyes of Matias Garcia, who died in the Arizona desert during a failed attempt to enter the United States. The "Facts & Stats" section provides current research and information about U.S. immigration policy.

Chicago Tribune Coverage of Elvira ArellanoThe Chicago Tribune has chronicled Elvira Arellano's plight since August 2006, when she first took sanctuary in Adalberto Memorial United Methodist Church. This special report includes a slideshow with audio accompaniment and a photo gallery illustrating Arellano's story.

VivirLatino Blog Coverage of Elvira Arellano
This Latino blog taps into the voices of the communities who have a personal investment in Arellano's case. Feedback to this blog represents all sides of the immigration reform debate.

The Chicago Minuteman Project
Part of a controversial activist organization, the Chicago chapter of the Minuteman Civil Defense Corps has been vocal in its belief that Arellano should be deported. Its Web site explains the group's beliefs and includes a blog on current activities.

La Familia Latina Unida (United Latino Family),
Founded by Elvira Arellano, this organization advocates legislative reforms to prevent illegal immigrants from being separated from their American-born children. Working through the United Methodist Church, the group outlines its mission and current initiatives in English and Spanish on this Web site.